1. Field of the Invention
The present invention relates to a battery pack and a method of manufacturing the same, and more particularly, to a battery pack including a battery case configured to realize an increased battery capacity and an improved strength against external impact, and a method of manufacturing the same.
2. Description of the Related Art
There is a need for a portable electronic apparatus that is capable of performing various functions and be used for a long time. As such, due to their higher battery capacities, lithium secondary batteries have now been utilized as power sources for portable electronic apparatuses.
In secondary batteries, a battery case can be in the form of a metal can. Alternatively, in lithium polymer secondary batteries, a multi-layered pouch-shaped structure composed of an aluminum (Al) foil and a polymer film can be utilized as a battery case.
In order to increase the battery capacities of lithium secondary batteries, high capacity negative and/or positive electrode materials and/or thinner battery cases have been utilized. For example, when using a metal can as a battery case, the use of a thinner metal enables an increased amount of an electrode active material, thereby achieving higher capacity and higher charge/discharge efficiency of batteries. However, there is a limit in how much the thickness of the metal can be reduced. On the other hand, when using a multi-layered pouch-shaped structure as a battery case, it is possible to reduce the thickness of the battery case to a desired level and to achieve a significantly reduced battery weight as compared with the use of a metal can, but there arises a problem of insufficient strength against external impact.
Also, in the fabrication of a typical secondary battery, there is a need to separately perform a process of manufacturing a battery cell and a process of assembling the battery cell and a protection circuit into a pack, which makes the entire battery fabrication process complicated and time consuming.